What does “not run” mean in R help pages?

Question

Sometimes on an R help page the phrase \"not run\" appears in comments. Check out this from the help page for \"with()\":

Examples
require(stats); require(gr         


        

Answer 1

This adds \donttest{} and is taken (verbatim) from @hadley's R Packages.

However for the purpose of illustration, it’s often useful to include code that causes an error. \dontrun{} allows you to include code in the example that is never used. There are two other special commands. \dontshow{} is run, but not shown in the help page: this can be useful for informal tests. \donttest{} is run in examples, but not run automatically in R CMD check. This is useful if you have examples that take a long time to run. The options are summarised below.

Command      example    help       R CMD check
\dontrun{}                 x
\dontshow{}       x                          x
\donttest{}       x        x